- Dynamic. “Conventional,” or coil,
dynamic microphones use a system of a diaphragm (membrane) and a coil that is placed in a magnetic field. From sound vibrations, the membrane, and with it the coil, begin to move, and an electrical signal is generated in the coil. Such models are relatively inexpensive, durable and reliable, and also cope well even with very loud and harsh sounds; in addition, they are more compact and lighter than the other type of dynamic microphones - ribbons (see below). Their main disadvantage is poor efficiency at high frequencies.
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Dynamic (tape). A variation of the dynamic microphones described above, in which the membrane is connected not to a coil, but to a thin (several microns) metal tape, hence the name. Historically, this is the first type of microphone with a dynamic operating principle, however, due to a number of shortcomings, it gradually lost wide popularity, giving way to coil-based options. Such disadvantages are, first of all, large size and large mass, complexity and high cost of production, as well as very low output impedance, which complicates the work with amplifiers. At the same time, tape models are characterized by extremely high accuracy of sound transmission over the entire frequency range, which allows them to be used in recording studios, at high-profile concerts, etc. Most modern models of this type are professional models, in particular studi
...o ones (see “Purpose”).
— Condenser. The name of this type is due to the fact that the microphone is actually a capacitor, in which the role of one of the plates is played by a sensitive membrane (usually made of a metallized polymer). Due to the vibration of the membrane (under the influence of sound vibrations), the distance between the plates and, accordingly, the capacitance of the capacitor changes - these fluctuations in capacitance provide an electrical signal. Condenser microphones have uniform sound transmission over the entire frequency range, with a minimum of distortion, due to which this technology has found wide application in professional audio equipment. It is worth considering that for such a device to operate, additional power is required - the so-called. “phantom” (standard voltage - 48 V). However, this cannot be called a clear disadvantage, because amplifiers, receivers and other high-end equipment are often made with this requirement in mind. But obvious disadvantages include high price, sensitivity to shock and strict requirements for temperature and humidity; the latter makes condenser microphones poorly suited for outdoor use.
— Capacitor (tube). A specific type of condenser microphones described above. They use the same principle of sound production (with all the advantages and disadvantages), however, the amplification element in such models, in accordance with the name, is built on vacuum tubes. Technically, such an amplifier introduces more distortion into the signal than a transistor one, but this distortion gives the sound a characteristic coloring that is pleasant to many listeners. Simply put, you get that notorious “warm tube sound”; Moreover, achieving such an effect using a microphone is cheaper than using a tube amplifier, and for a number of technical reasons this option often turns out to be optimal. Almost all tube microphones have a studio purpose (see above). Their main drawback is their high price (several times more than that of “regular” capacitor analogues). In addition, such models have their own nutritional characteristics; To supply energy, a special adapter is usually supplied, which is also responsible for controlling additional functions such as changing the radiation pattern.
- Electret. In design, such microphones are similar to the condenser ones described above, but their design includes a plate made of the so-called. electret - substances with special electrical properties. This provides a number of advantages: electret microphones can be used outdoors without much difficulty, they can be made more compact, and such models are cheaper to produce; At the same time, the quality of sound transmission can be quite comparable to condenser ones. As a result, this technology is found in a wide variety of models - from miniature lavaliers and simple computer ones to studio ones (see “Purpose”). Note also that electret microphones also require external power, but this is not always phantom 48 V - for some varieties, a small amount of energy is sufficient, which can be provided by a compact battery or power supply via a 3.5 mm mini-Jack cable.Sensitivity describes the signal strength at the output of a microphone when it processes a sound of a certain volume. In this case, sensitivity means the ratio of the output voltage to the sound pressure on the membrane, expressed in decibels. The higher this number, the higher the sensitivity. Note that, as a rule, values in decibels are negative, so we can say this: the closer the number is to zero, the more sensitive the microphone. For example, a -38 dB model outperforms a -54 dB model in this parameter.
It should be borne in mind that high sensitivity in itself does not mean high sound quality - it only allows the device to “hear” a weaker sound. Conversely, low sensitivity is not an unequivocal sign of a bad microphone. The choice for this parameter depends on the specifics of the application: a sensitive device is useful for working with low sounds and in cases where it is necessary to capture the smallest nuances of what is happening, and a “weak” microphone will be convenient at high sound volume or, if necessary, filter out extraneous weak noises. There are models with
sensitivity adjustment(and for models with a headphone output
, headphone volume control may be provided).
